Re: how to tweak kernel to get the best out of kvm?

2010-04-23 Thread Alec Istomin
Hi there! I'm trying to understand kvm performance bottleneck and I was hoping to get sharing statistics form ksm. Was not able to locate it so far, the below mentioned /sys entry is missing, while ksm module is loaded. I'm using latest from rhel 5 x64: 2.6.18-194.el5, kmod-kvm-83-164.el5 and I'm

Re: how to tweak kernel to get the best out of kvm?

2010-03-15 Thread Harald Dunkel
On 03/13/10 09:54, Avi Kivity wrote: If the slowdown is indeed due to I/O, LVM (with cache=off) should eliminate it completely. As promised I have installed LVM: The difference is remarkable. My test case (running 8 vhosts in parallel, each building a Linux kernel) just works. There is no

Re: how to tweak kernel to get the best out of kvm?

2010-03-13 Thread Avi Kivity
On 03/11/2010 03:24 PM, Harald Dunkel wrote: Hi Avi, I had missed to include some important syslog lines from the host system. See attachment. On 03/10/10 14:15, Avi Kivity wrote: You have tons of iowait time, indicating an I/O bottleneck. Is this disk IO or network IO? disk.

Re: how to tweak kernel to get the best out of kvm?

2010-03-11 Thread Harald Dunkel
Hi Avi, I had missed to include some important syslog lines from the host system. See attachment. On 03/10/10 14:15, Avi Kivity wrote: You have tons of iowait time, indicating an I/O bottleneck. Is this disk IO or network IO? The rsync session puts a high load on both, but actually I do

Re: how to tweak kernel to get the best out of kvm?

2010-03-10 Thread Avi Kivity
On 03/10/2010 02:58 PM, Harald Dunkel wrote: Hi Avi, On 03/08/10 12:02, Avi Kivity wrote: On 03/05/2010 05:20 PM, Harald Dunkel wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi folks, Problem: My kvm server (8 cores, 64 GByte RAM, amd64) can eat up all block device or file

Re: how to tweak kernel to get the best out of kvm?

2010-03-10 Thread Javier Guerra Giraldez
On Wed, Mar 10, 2010 at 8:15 AM, Avi Kivity a...@redhat.com wrote: 15 guests should fit comfortably, more with ksm running if the workloads are similar, or if you use ballooning. is there any simple way to get some stats to see how is ksm doing? -- Javier -- To unsubscribe from this list:

Re: how to tweak kernel to get the best out of kvm?

2010-03-10 Thread Avi Kivity
On 03/10/2010 05:57 PM, Javier Guerra Giraldez wrote: On Wed, Mar 10, 2010 at 8:15 AM, Avi Kivitya...@redhat.com wrote: 15 guests should fit comfortably, more with ksm running if the workloads are similar, or if you use ballooning. is there any simple way to get some stats to see